Field of the Invention
The invention relates to a device for emission of laser radiation with one or a plurality of pumped active zones of a semiconductor laser, the zones being disposed within a resonator.
Semiconductor lasers are generally known and are usually produced in two embodiments. In the case of edge-emitting laser diodes, the emission is effected in the direction of extent of the pumped active layer and the laser radiation emerges through the edges of the active layer. This type of laser diodes generally exhibits poor beam quality because the edge-emitting laser does not oscillate in one mode and does not oscillate exclusively in the fundamental mode. Thus, the laser radiation is emitted in a wide angular range. This is a pronounced problem particularly in the case of edge-emitting laser diodes whose active zone has a large extent transversely with respect to the optical axis of the resonator.
In addition to the edge-emitting laser diodes, surface-emitting diodes are also known, in which the laser radiation is emitted at right angles to the pumped active layer. The surface-emitting laser diodes are afflicted, on one hand, with high electrical resistances based on the limited dopability of mirror layers formed on both sides of the active zones. Although the resistances can also be reduced, inter alia, by increasing the diameter of the active zone, this generally has the effect that higher modes start during the operation of the laser, which modes impair the beam quality.